1. Field
One embodiment of the present invention relates to a perpendicular magnetic recording head having a side shield, and a magnetic disk apparatus including the perpendicular magnetic recording head.
2. Description of the Related Art
In magnetic disk apparatuses of a perpendicular recording system, a perpendicular write head performs recording on a magnetic disk near the trailing edge of a main pole. However, if the perpendicular write head is located over the inner or outer periphery of the magnetic disk, the longitudinal direction of the main pole may skew significantly relative to the track direction. The write head at a high skew angle causes a writing operation to be performed not only at the trailing edge of the main pole but also at the side edge. In this case, the side edge of the main pole may disadvantageously erase a part of signals already recorded in the adjacent track (side erase). When the guard band width between recording tracks is increased in order to avoid the possible side erase at the side edge of the main pole, the track density is hard to be improved.
A perpendicular write head has been known which has a main pole, an auxiliary pole (return pole), and a side shield processed to surround the trailing edge and side edge of the main pole in the air bearing surface. The side shield extends from the vicinity of the trailing edge of the main pole to the auxiliary pole, with the trailing edge of the side shield joined to the auxiliary pole (Jpn. Pat. Appln. KOKAI Publication No. 2005-190518). The perpendicular write head can reduce the erase width by the side edge of the main pole because of the presence of the side shield. However, the side shield configured as described above may degrade the recording ability of the main pole directly under thereof, resulting in insufficient overwriting. Thus, disadvantageously, high signal quality cannot be achieved.